Spooling device for cable tool drills



March 27, 1945. H. w. THORNBURG 2,372,232

SPOOLING DEVICE FOR CABLE TOOL DRILLS Filed Aug. 13-, 1942 2 ,sheetssheet 1i I -Maw ATTORNEYS,

H. W. THORNBURG SPOOLING DEVICE FOR CABLE TOOL DRILLS March 27, 1945.

Filed Aug. 13, 1942 2 Sheets-Sheet 2 V INVE BY 2am I'/ ATTORNEY 5 coilsto become crossed over other coils.

Patented Mar. 27, 1945 SPOOLING DEVICE FOR CABLE TOOL DRILLS Herbert W.Thornburg, South Milwaukee, Wis.,

assignor to Bucyrus-Erie Company, South Milwaukee, Wis., a corporationof Delaware Application August 13, 1942, Serial No. 454,641

11 Claims.

My invention relates to new and useful im-- provements in spoolingdevices for cable-tool dril1s.

Such drills, per se, are well known.

In such drills a rope passes, from a winch drum on the main frame,around a heel sheave at or near the pivot of a spudding beam, thenceunder a sheave at oscillating end of the spudding beam, thence over asheave at the upper end of a mast, and thence vertically downward intothe hole useful details, which will be readily evident as thedescription progresses.

My invention consists in the novel parts and in t the combination andarrangement thereof, which which is being drilled in the ground. At thelower end of this rope is a string of percussion drillingtools. Thespudding beam is oscillated by a pitman, actuated by a rotating crank.As the rope is payed out to lower the tools as the hole grows deeper, oris taken in to withdraw the tools for any reason, it is desirable thatthe reach of rope from the winch-drum to the heel sheave shall move fromside to side, always in a plane perpendicular to the axis of the drum,

spooling the lays of the rope evenly off of or onto the drum; and thatthe heel sheave shall move from side to side and change its orientation,so as always to lie substantially in the plane defined by the tworeaches of rope which run from this sheave.

v Accordingly it is the principal object of my invention to devise amounting for the heel sheave, such that the heel sheave willautomatically thus move and thus orient itself, under the influencemerely of the tension in these two reaches of rope.

During spudding, there is a tendency to throw slack into the rope at theend of each upstroke of the tools. Furthermore, on the downstroke therope is stretched and has a tendency to untwist; and, when the ropebecomes slack a the end of the upstroke, the rope tends to it st upagain.

The net result of these tenden ies is for the coils of rope on the drumto expand, and for some This damages the rope. I

So it is necessary for a spooling device, in addition to properlyshifting and orienting the heel sheave, also to clamp the rope just,sufiiciently tightly to prevent this whippin and twisting, and yetpermit the gradual slipping of the rope past the heel sheave as the tooldig the hole deeper and deeper. Such a clamping means should also bereadily releasable during hauling up or lower ing of the tools.

Accordingly it is a further object of my invention to incorporate intomy spooling device such a clamp.

In addition to my principal objects, above stated, I have worked out anumber of novel and are defined in the appended claims, and of which oneembodiment is exemplified in the accompanying drawings, which arehereinafter particularly described and explained.

Throughout the description, the same reference number is applied to thesame member or to similar members.

Figure '1 is a plan view of a drill embodying my invention.

Figure 2 is a side elevation of the same drill.

In these two figures, the associated parts of the drill have been shownvery schematically, and much of the drill (well known to the art) hasbeen omitted.

Figure 3 is a slightly enlarged elevation of one of the links of myinvention, taken along the lines 3-3 of Figure 1.

Figure 4 is a slightly enlarged elevation of the heel sheave of myinvention, taken along the lines 4-4 of Figure 1.

Figure 5 is a geometric diagram showing the path of the center-point ofmy heel sheave, and the orientation of that sheave. This diagram isenlarged to six times the scale of Figures 1 and 2.

Referring now to Figures 1 and 2, we see that II is the'main frame of adrill, supported by wheels l2, and during drilling by blocks l3.

The frame It supports a mast l4 (called -derrick in the art), a motorIS, a winch IS, a

spudding gear l1, and associated driving connections, not numbered.

From the winch IS, a rope I8 runs around a heel sheave l9, thence undera spudding-sheave 20, thence over a sheave (not shown) at the top of thederrick l4, thence down to the drilling tools (not shown).

The spudding gear I1 is clutched to and unclutched from a driveconnection with the motor l5, by means of a clutch (not shown).

The spudding-sheave 20 is mounted (preferably by means of an offsetsubstantially vertical pivot 2|). on the free end of a spudding-beam 22,which in turn is pivoted on horizontal pivots 23 on the frame ll.

The spudding-beam is rocked up and down by the rotation of the spuddinggear l1, acting through pitman 24.

The winch I6 is controlled by means of a conventional drive, clutch,brake, and hand-levers (not shown).

The operation of all these conventional parts will be readilyunderstood.

Heel sheave i9 is free to slide laterally along a floating rod 25, theends of which are pivoted on swinging brackets 26, which in turn arepivoted on the frame I I. As shown, sheave l slides on rod 25, and turnsabout that rod as an axis. But, although highly advisable, this is notnecessary. Any alternative device, whereby sheave i9 is rotatablymounted, and is free to slide along rod 25, would be sufiicient.

The ivot axes A and B, between the brackets 26 and the frame H, and thepivot axes C and D between these arms and the rod 25, might preferablybe so inclined that the plane in which rod 25 moves, will be somewhatupwardly inclined away from the drum it.

My machine was originally built in this manner. But I have found that acons derable angular departure from the theoretically optimumarrangement is possible without appreciably reducing the effectivenessof my invention. And I have found that the theoretically optimumarrangement unfortunately permits the entire linkage to flop aroundbadly, under the influence of gravity alone, if the rope l8 beslackened. Accordingly I have been forced to compromise betweentheoretical and practical considerations, by so placing my pivots thatrod 25 movesin a horizontal plane. 7

Of course, I could have biased my linkage against flopping by the use ofcounterweights or springs; but, finding the simpler expedient to besuccessful in practice, I adopted it Preferably CD should beapproximately onehalf AB; and, when CD is parallel to AB, then AC and BDshould each form an angle of 45 degrees with AB. But structuralconditions frequently prevent the attainment of this optimum, which canbe considerably departed from, without appreciably reducing theeffectiveness of my invention. With CD more than one-half AB (as shown)I have found that the angle shoul be more than 45 degrees.

Turning now to the geometrical diagram which constitutes Figure 5, wesee that that figure represents the right half of the linkage of myinvention. AC and AC" represent the two extreme positions of theright-hand bracket 26; and C'D and CD represent the correspondingpositions of rod 35. C"0 represents half the path of the center of heelsheave US, which is diagramatically illustrated in one of its positions,properly ori ented. The center-line of the machine is marked with themonogram CL.

By virtue of my linkage, my heel sheave i9 always lies in a position ofstable equilibrium in which the lower reach of rope i8 alway lies in aplane perpendicular to the axis'of the drum it, and hence all positionsof this rope are parallel to all other positions thereof, and the sheaveis always oriented in such a way as to be very nearly in the plane ofthe two reaches of rope 58.

Furthermore, the slight frictional drag of sheave it on rod 25 issufiicient to cause it to lag very slightly behind its proper position,thus ensuring a tight lay of the rope on the drum.

By virtue of its swivel, spudding sheave 2E3 always lies in the plane ofthe two reaches of rope running to it.

Turning now to Figure 4, we see heel sheave l9 on rod 25, the latterbeing shown in crosssection. A rope guard 27 is also journaled on rod 25at each side of the sheave. A shoe 28 fits in an opening between ribs 2tand 30 of the guard 2'7. This shoe is constrained by spring 3| and asimilar spring on the further side, to bear against the rope, clampingit to the sheave.

The guard 21 is kept from rotating, by beam 32, which slides betweenprojection 33 on the guard and. projection 34 on the shoe. Pivoted onthe shoe 23 is a cam 35. By inserting a bar in the socket 36 of thiscam, and rotating the rod downward through 90 degrees, the cam will bearagainst the edges of the guard 21, holding the shoe out of clampingposition, and thus permitting the rope to run freely.

Having now described and illustrated one form of my invention, I wish itto be understood that my invention is not to be limited to the specificform or arrangement of parts herein described .and shown, except alimited by my claims.

I claim:

1. A spooling device, comprising: a first sheave; a fixed position drum;a floating sheave; these three elements being adapted to be used inconnection with a cable wound around the drum and thence extendin aroundthe floating sheave and thence around the first sheave; means,comprising a rod on which the floating sheave is slidably mounted,constraining the floating sheave to follow such a path that the reach ofrope from the drum to the floating sheave will always lie substantiallyin a plane perpendicular to the axis of the drum, and the floatingsheave will always lie perpendicular to its path and substantially inthe plane of the two reaches of rope which extend from it; a floatingsheave-guard for embracing the floating sheave, and floating therewith;and means to prevent the sheave-guard from rotating with the floatingsheave.

2. A sheave-mounting, compr sing: a widespread base; two converginglinks, each hinged at one end of the base; a rod, materially shorterthan the base and hinged at each end to one of the links; and a sheavemounted for lengthwise sliding along the rod.

3. A kinematic mechanism, comprising: a widespread base; two converginglinks, each hinged at one end of the base; a rod, materially shorterthan the base and hinged at each end to one of the links; a movablemember mounted to slide along the rod, and to remain at a constant anglethereto; and means to constrain the movable member to occupypredetermined positions in space under respective conditions.

4. A spooling device, comprising: a first sheave, with a substantiallyhorizontal axis; a fixed position drum, with a substantially horizontalaxis; a wide-spread base; two converging links, each hinged at one endof the base; a rod, materially shorter than the base and hinged at eachend to one of the links; and a sheave mounted for lengthwise slidingalong the rod; the plane of the base, the links and the rod, beingsubstantially horizontal; the relative location of the drum, the rod,and the sheave being such that a rope extending from the drum can runfirst over the sliding sheave and then over the first sheave.

5. A spooling device, comprising: a flrst sheave; a fixed position drum;a floating sheave; a rope, leading from the drum, thence around thefloating sheave, and thence around the first sheave;

and means including a floating straight rod on which the floating sheaveis slidably mounted, and so restricting and controlling the movement ofthe floating sheave as to constrain the floating sheave to be inpositive equilibrium, under the tension of the rope, when, and onlywhen, the

reach of the rope extending from it to the drum is substantiallyperpendicular to the axi of the drum; said means also constraining thefloating sheave to lie alway substantially in the plane defined by thetwo reaches of the rope extending from it.

6. A spooling device, comprising: a, first sheave; a fixed positiondrum; a floating sheave; a rope, leading from the drum, thence aroundthe floating sheave, and thence around the first sheave? and meansincluding a floating straight rod on which the floating sheave isslidably mounted, and so restricting and controlling the movement of thefloating sheave as to constrain the floating sheave to be in positiveequilibrium, under the tension of the rope. when, and only when, the

, reach of the rope extending irom it to'the drum lies ina planesubstantially perpendicularto the axis of the drum.

7. A spooling device. according to claim 1, iur-.

- ther characterized by having: a shoe carried by the sheave-guard: andmeans to constrain the shoe to yieldably clamp any cable trained aboutthe floating sheave against the floating sheave.

8. A spooling device, according to claim 1, further characterized byhaving: a shoe carried by the sheave-guard; means to constrain the shoeto yieldably clamp any cable trained about thefloating sheave againstthe floating sheave; and means for optionally re1iev. ng thisconstraint.

9. A spooling device, according to claim 1, further characterized byhaving: a shoe carried by the sheave-guard; means to constrain the shoeto yieldably clamp any cable trained about the floating sheave againstthe floating sheave; and means for optionally relieving this constraint;said last named means consisting of a cam, pivoted on the shoe, androtatable to bear against the sheave guard.

10. A spooling device, according to claim 1, further characterized byhaving: a shoe carried by the sheave-guard; means to constrain the shoeto yieldably clamp any cable trained about the floating sheave againstthe floating sheave; and meaneior optionally relieving this constraint;said last named means consisting of a cam, pivoted on the shoe, androtatable to bear against the sheave-guard, and having means. for theattachment of a lever to rotate the cam.

-11. A sheave-mounting, comprising: a widespread base; two converginglinks, each hinsed at one end or the base; a rod, materially shorterthan the base, hinged at each end to one of the links; and a sheavemounted directly on the rod, for rotation about the rod, and for slidingalong the TM.

HERBERT W. THORNBURG.

